


Aeternum

by gAAmAtsU16



Category: Haikyuu!!
Genre: Alternate Universe - Fantasy, Demon Oikawa Tooru, Fluff and Angst, In Media Res, Knight Iwaizumi Hajime, M/M, Reverse Chronology, Slight Memory Loss, We start at the end guys!
Language: English
Status: In-Progress
Published: 2019-10-05
Updated: 2019-10-05
Packaged: 2020-11-24 12:11:09
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings, Major Character Death
Chapters: 1
Words: 4,057
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20907467
Author URL: https://archiveofourown.org/users/gAAmAtsU16/pseuds/gAAmAtsU16
Summary: Aeternum(n). forever"And he laughs at the absurdity of the timing because he knows he’s dying and yet, Tooru’s pouty face bombards him mentally like a violent reminder of who he’s leaving behind and his heart constricts some more."





	Aeternum

**Author's Note:**

> HIT WITH THE IWAOI FEELS HARD! THIS IS REVERSE NARRATIVE GUYS, WE START AT THE END AND VICE VERSA \\(TvT)/

“Hajime.”

He turns around. And drops the groceries he’s carrying. The fruits tumble down the porch of his apartment but he doesn’t care.

The one who called him, a man of brown hair and eyes, looks at him through piercing hazel across the street as he reaches out a hand like he wants to touch him from the distance between them. Iwaizumi could read so many emotions on his face it's dizzying.

It's...dazzling.

_Do I know you? _was at the tip of his tongue. Except he feels it. Right down to his veins. This stranger was no stranger.

Not at all.

Not a bit.

He can’t explain why tears fall from his eyes and a name pops out his mouth like on autopilot. “Tooru.”

The stranger smiles against a tear-stained face and he runs towards him. Iwaizumi opens his arms expectantly. He still wasn't sure what the hell is happening.

But suddenly, everything felt _right_ in the world.

* * *

“…Ha…ji…me…”

Each syllable was spoken with chagrin. Each puff of breathe, each low inhale, each gasp was all _pain, pain, pain._

Iwaizumi wasn’t the one with a blade through his heart but there was a lump in his throat, like a rock lodged so deep no air is ventilated through even the smallest of airways.

The creature- the _monster, _stood with stillness like dark ice fractals, graceful in its motionlessness, beauty in its monstrosity. It grasps the hilt of the blade where Iwaizumi was holding.

Iwaizumi looks up through misty lashes. “Why do you know my name?”

A smile. So small that if not for their close proximity would escape his eyes. “My…name…”

“Why do you _know_ my name? How do you know me?” Anger laces Iwaizumi’s voice. His hands that once itched to kill now presses to cup at the nape of the demon king. “Answer me, damn it!”

“My…name…” the demon’s entire body wracked with ugly coughing, blood oozing from the corner of his mouth, “Tooru…is what…I was formerly…called…I think?...” Cough, more blood, “Yes…when I still-still had…humanity…”

The name was like a trigger. It jolts Iwaizumi’s core, upsets his focus, imbalances his boldness.

“What—“

Voices. Beyond the fort. Iwaizumi picks up the subdued noise of steel meeting steel and the cacophony of the dialect he’s grown accustomed to over the years hollering amongst the winds. His fellow warriors approach. Victory was slithering their way.

The demon crumples down, loses his strength completely, bringing Iwaizumi down with him with the force. On instinct, he let’s go of his sword and grasps the demon’s shoulders who cringes as his body slumps weakly into his. They slid on the pavement.

“And…and Tooru…he had…a Hajime. Without him…he…I was…mortal…” He continued to sputter nonsense but the words were not sieved out of Iwaizumi’s mind. It stays there and topples the emptiness brick-by-brick like he _should_ know about all this.

Iwaizumi’s vision was blurring and he doesn’t even know why! “Who are you?” He asks, desperation laces his tone. There was so much he could not remember but _this,_ he feels he needs to remember.

“Tooru—was it? Yes, Tooru…he…is terrible at everything. Including…forgetting you.” Iwaizumi’s breath hitched in his throat. The demon’s eyes are faraway like reminiscing about something from the past. “Is it bad…that he…_I _miss you so much, that you are always…the only thought on his mind? Tooru, no, not Tooru. Me…I think it is me that misses…Hajime so. I try hard… to make myself not miss you… but when all is said and done,” a chuckle full of ache, “I still do.”

“What are you babbling about?!” _Goddamn, make it stop. __I don't want to see him in pain. _“What—“

He’s stopped by a pair of cold lips against his. Very cold. Very inhuman. Iwaizumi’s entire body shuts down, zeroes in on nothing but the filthy monster in his arms. He should be disgusted but he finds himself leaning in, pressing closer as his arms wove around a lithe body and disheveled hair. It feels so _natural_, having him like this. So fitting.

So...

As the breeze warms and the first light of dawn cascades on the stone fortress, Iwaizumi’s comrades find him crying with the dead demon king in his arms.

* * *

He barely dodges the swipe Matsukawa aims at him. He pivots on his left foot and swings his body around to block the strike. Their swords clang in angry greeting.

“Left your mind up at the clouds again, Iwaizumi?” Matsukawa gives him a sleazy grin as he pushes further. “You should be dead by now.”

It was a regular banter between the two but the humor escapes Iwaizumi as he staggers back like an invisible force punched him. _You should be dead by now._

Matsukawa was by his side immediately, a hand steadying him. “You all right?” His brows crunch in worry.

“I’m fine.” Iwaizumi insists even if he feels the familiar headache wrack his skull once more. He shakes the ache away.

His sparring partner doesn’t seem convinced. “When you say you’re not it makes all of us worry some more, midget.” He ruffles his black hair, and he laughs as the shorter man swats his hand away in annoyance. “But seriously, I think we need to cut today’s training short. Your wounds haven’t healed up that well yet and Sugawara would no doubt murder me when he discovers we’re having this secret spar behind his back.”

“Suga is such a mother hen.” Iwaizumi smiles despite the accusation but it falls quickly. He remembers nagging profusely to someone before too. Over lack of health ethics? Was it Kindaichi? Or Kyoutani? He rubs his temple, trying to discern who but his mind remains blank.

Matsukawa mistakes his action as him soothing a tormenting headache and probes at his chest gently. “Get some rest. Those injuries are still fresh and it’s not healthy enough you keep getting these black-outs in the middle of a warfare.”

Iwaizumi sighs. “You’re right. I can’t- they attack me underhandedly often. I can’t stop them from happening.”

“You mean the black-outs?”

He nods dejectedly.

“I wouldn’t be so surprised.” Matsukawa steers towards the brass doors, prompting Iwaizumi to follow. “I mean, you were in a very bad shape when the scouts rode through the wreckage. Heck, they didn’t expect anyone to survive the front lines at all and yet, they carry you back more dead than alive, drenched in blood all over with major wounds in various life-threatening areas. Having these memory blocks is the least of everyone’s worry. They’re more focused on _how_ you were alive.”

“Thank you for that colorful description.” Iwaizumi frowns at his friend who gives him a nonchalant shrug. “That’s such an exaggeration.”

“Clearly, you haven’t seen yourself after they wheeled you in, my friend.” Matsukawa pats his shoulder, tone serious. “You were dead, Iwaizumi. At least to all of us. Your skin was alabaster and we saw more crimson on any patch of flesh left on you. If it weren’t for the fact that your heart was beating they would’ve carried back a corpse.”

“But then I was alive.” Even today, Iwaizumi couldn’t grasp the logic how he was able to though. He prided himself with an iron-will but when Suga, the village’s best physician described the state of his injuries and expressed his confusion and marvel why Iwaizumi indeed survived, made him more skeptical of his self-proclaimed salvation.

“Everybody calls it a miracle.” Matsukawa chuckles darkly, “So you see why everybody throws you the phrase, ‘you should be dead by now’ on a daily basis? Because it’s true. You really should be.”

* * *

The arrow sinks deep into his chest. He feels the tip puncture his heart and he knows, with dreaded clarity his time is ticking rapidly. He tries to move but he falls on his knees instead and the many other arrows embedded in his body sinks further and he screams.

He couldn’t even assess his state. All he knows is that everything hurts; pain pours out his pores and so does blood. Lots of it. They gush out like holes in a liquid bag, flowing and spurting, pooling beneath him.

His vision dims and his mind swims in tar. All around him, the sounds lose their intensity and he forgets he’s in the middle of a battle when a face appears in his mind. _My Tooru. _Beautiful, strong and passionate. And he laughs at the absurdity of the timing because he knows he’s dying and yet, Tooru’s pouty face bombards him mentally like a violent reminder of who he’s leaving behind and his heart constricts some more.

Somebody was yelling but then, everywhere is all noise.

He closes his eyes, the lids so heavy anymore and his body sways backwards. He prepares himself to feel another wave of pain should he fall and allow the dozen arrows penetrate him further but no intense pain comes. Instead, there was a warmth oh so familiar, a scent so alluring and a voice filled with anguish and panic.

“….jime….ha….ime….” It’s so fuzzy but strangely near. Iwaizumi is disturbingly soothed by the voice. “…Hajime! HAJIME!”

He opens his eyes and feels disappointed that all he sees is a blur. There was a face near him, so close he could feel his breathe ghost over his face. But he doesn’t need to recognize who this savior was that granted him companionship on his dying moment. “Tooru…” he says with certainty. This was his Tooru. Still beside him, always with him even at this time.

“Hajime, open your eyes. Listen to my voice.” It was like a lull. He hears buzzing and a prickly sensation on his torso. Iwaizumi finds himself closing his eyes instead.

Tooru’s voice became more frantic, the foggy image more fidgety. “No! No, don’t close them! Hajime, stay with me!”

He’s near his end. He knows this. His heart rate slows. His pulse diminishes. He summons all strength the kami’s can bestow upon him to utter what he knows are very crucial, very important words.

To his savior, his love, his life, he says with conviction.

“I love you.” And his world goes black.

* * *

It wasn’t the first time he and Tooru fought. They’ve had hundreds of arguments that would shame married couples but this was probably the only time they put off seeing each other the longest. It has been ten days, and Iwaizumi feels the unsettling feeling of remorse in his gut. That, and the fact that he misses the petulant bastard so much.

He strides into the dark castle walls, ignoring the vile aura radiating in the atmosphere. Years haven’t taught him to fully negate the malicious stench of the palace but he’s grown tolerant of it. Tooru seldom leaves these walls after all and Iwaizumi was left to do most of the visitations.

He meets Kuroo outside Oikawa’s chambers. The tall lanky demon gives him an unimpressed scowl but moves aside to let him enter. He opens the door with caution, aware of what state he’ll find the owner in. He moves to the side and shuts the door just as a silver knife thuds into the surface of the oak doors, Kuroo’s barely audible “Oi, oi, oi” resonates from the other side.

He eyes the blade with a raised brow and calls to the perpetrator with a cool voice. “Were you aiming for the door or my head?”

A figure darts from the bed and Iwaizumi is slammed back harshly. He grunts and looks up to see twin red orbs frowning at him.

“I don’t need to aim when I could simply slit your throat up at this proximity.” The hand on his neck tightens. The claws sting his skin and any deeper would result to cuts.

Iwaizumi doesn’t flinch at the threat. He shuffles forward in a similar fast move and kisses his attacker aggressively who returns it just as quick, just as eager. The hand falls from his neck, goes to his chest and he uses the distraction to weave an arm around the taller man’s waist and reverse their position. He pushes in deeper through his mouth; his tongue prods his orifice as it coils around the other. They both moan.

“You’re such a load of crap, Shittykawa.” Iwaizumi pulls back to smirk smugly at his partner before going for his throat, biting at the junction between his neck and shoulder.

Oikawa yelps and opens his eyes. They were hazel-colored. “Iwa-chan, so mean.” He shivers when Iwaizumi licks a trail from his clavicle to under his jaw. “You took so long to make amends.”

Iwaizumi scoffs. “I’m not the only at fault, trashface. I’d blame 60% of this conflict to your immaturity and denial to accept you’re an idiot with horns.”

“Wow, how are you able to be so harsh and consoling at the same time?”

“Dealing with you is high-maintenance.” He laughs when Oikawa pouts at him. He kisses his lips again to compensate and says softly. “I’m sorry.”

That dispels the anger out of Oikawa. He snakes his hand around Iwaizumi’s neck and brings their forehead together. “I’m sorry too. I mean, I know I was being childish but I can’t help it. I’m selfish when it comes to you.”

Iwaizumi chuckles warmly. He slides his palms at Oikawa’s waist and pecks lovingly at the area where his horns sprout from the crown of his head. Oikawa hums at the gesture. “I know.” He gently lifts Oikawa as the demon crosses his legs around his hips and they transfer to his massive bed.

“Hajime,” the hesitation was palpable and Iwaizumi delivers a kiss to the corner of his mouth for reassurance. “I really can’t change your mind?”

The black-haired smiles lowly. Oikawa was pretty stubborn. Sadly, so was he. “I’ll come back to you. I promise. After the battle, I'll return to you.”

Oikawa doesn’t look like he believes him. He tightens his embrace on him, nuzzling into his neck, inhales his handful of Iwaizumi. “Sometimes I think mortals have more bloodlust than demons. They never cease to find something to fight about and many lives are destroyed in the process.”

Iwaizumi unbuttons his dress shirt, and slides his palm over the milky expanse of Oikawa's chest, pinching a nipple. “Are you sure you’re a demon, Trashykawa? You sound like you have a heart.” He doesn’t mean any of these words of course.

“Mean. I obviously have a heart. How else could you have captured it then?” The hand exploring his body stops and he whines at the loss of contact.

Butterflies began fluttering in Iwa’s chest and he blushes. “Damn, Tooru. How do you manage to make me fall for you every single time, you piece of shit.” His breath comes out ragged. He’s suddenly so hungry for this wonderful creature underneath his arms.

“Don’t add insult to the compliment, Iwa-chan.” Oikawa smiles up at him. He looks breathtaking under the moonlight. “Only for you. My magic is solely for you. I am only for you.”

Iwaizumi could ignore the claws, the fangs and the horns. All that is there is the man he loves and Iwaizumi slots their lips once more, staking his claim.

* * *

It’s so strange seeing tears on Oikawa’s face. It’s like, you can’t put a decent picture of it at how absurd it looks.

“Are you okay?” Iwaizumi asks with a subtle tinge of worry.

Oikawa inhales through his nose so loud he probably choked on some of his snot. “Am I okay? What the hell, Iwa-chan! Are _you_ okay?”

Iwaizumi blinks. “Hah?”

“God, you’re so stupid! I know you’re utterly reckless but you shouldn’t have taken the hit. I heal faster. I’m a demon. I don’t bleed that much. I—“

“Okay, okay, calm down,” Iwaizumi pats his forearm in comfort, “Tooru, calm down. Okay? I’m fine. I’m not that hurt.”

The coaxing seems to do Oikawa good. He closes his eyes, pauses for a few seconds and opens them in a more composed manner. “I’m good now.” He squeezes the hand on his arm and smiles. “I’m good. Turn around and lemme double check.”

Iwaizumi groans. “I told you I’m fi—“

“Turn around _now._”

The shorter one does as told; more irritated than afraid that Oikawa could boss him like this. He feels the familiar buzz of healing magic as Oikawa once more inspects his back. There really wasn’t any need for this. Iwaizumi feels fine. It’s Oikawa he’s more concerned about whose spending magic outside his realm. “Really, Tooru, I’m all right. I just hit the ground too harshly but I’m all good. Stop using your magic over something so trivial.” The other who’s usually quick to reply was quiet. Iwaizumi whirls his head when he mutters something behind him. “What?”

“I said it’s not trivial.” A green light shrouds Oikawa’s right palm but his brows furrow. He’s biting his lips. “It’s not trivial. Mortals are fragile. They’re vulnerable. You get injured easily and heal so slowly. You didn’t have to protect me when we fell. I could’ve flown us to safety or redirected our landing.”

“Hey,” his outstretched hand was squeezed by another. He looks up to see Iwaizumi giving him an intense stare. “Your eyes are red.” Oikawa blinks and takes a moment to compose himself. Iwa interlaces their fingers and continues. “I know you have super healing and all that but I didn’t wanna risk it.”

That puzzles Oikawa. “Why?”

Iwaizumi turns his head away. Oikawa notices his ears are slightly red. “Cause your wings would’ve been broken if we fell at that pace and you’d be in pain and I…don’t like seeing you hurt.” He whispers that last part, Oikawa has to mentally slap himself to convince himself he heard it right.

“Iwa-chan…” Iwaizumi grunts suddenly and clutches at his right shoulder. “Iwa-chan, what’s wrong?”

“N-nothing, my shoulder just flared up. It’s…going away now.” Oikawa raises his hand once more and Iwaizumi stops him. “No. No more healing.”

Oikawa pouts but retreats his arm. He looks contemplative. Then he scoots closer and to Iwaizumi’s alarm and embarrassment and _glee,_ kisses his shoulder blade.

“W-w-what the heck was that, Shittykawa?” He shoves the other out of instinct. Thankfully, it wasn’t that violent.

“Ow, Iwa-chan, is that how you say thanks to someone who’s trying to comfort you?” When he sees the confusion on his eyes he explains. “My…mother used to do that to me. She said when times that healing magic doesn’t work a good gentle kiss can soothe any ailment.” Now, he blushes and looks away.

Iwaizumi’s face heats up. "That's...ridiculous."

"Hey!"

"Do it again."

Oikawa gapes a second time. "What?"

Iwaizumi mumbles something incoherent but he removes the space between them. “Do that again.”

For a minute, Oikawa gawks at him, unsure. But the confidence and trust in Iwaizumi encourages him and he leans in again to kiss at his clavicle. Iwaizumi hums and Oikawa takes a bold step and kisses his cheek.

Before Iwaizumi second guesses himself, he takes Oikawa’s hand, pulling him flush against him. “Next time you take me flying, let’s not go to any higher altitude other than a sycamore tree. For both our sakes.”

He hears a soft intake of breathe and seconds after, a head slumps into his shoulder. Oikawa laughs quietly. “Let’s.”

* * *

They were playing by the brook when the cloak that Oikawa always wears slips off. Iwaizumi asked him why he insists to leave it on and he says he’s allergic to the sun. He realizes then he’s lying.

On top of Oikawa’s head, jutting out of his silky chocolate curls, were small barely visible horns like those of a ram.

Oikawa realizes too late what happens and folds in on himself. He kneels in reflex, a defense mechanism. He looks up at Iwaizumi with trembling lips and his eyes swirl in scarlet. Filled with horror. Filled with alarm. Filled with fear.

“What… are you?” His question was more out of curiosity than fear. This was Oikawa after all. If he wanted Iwa hurt, he'd have done so already many days ago.

Oikawa looks near tears and Iwaizumi wants that erased so he kneels in front of him too and pats his knee reassuringly.

The answer came too soft, too shy. “I’m a demon.”

Iwaizumi should be afraid. These were the very creatures his parents had warned him about that were dangerous and deadly and would take children in the dark of the night. He should turn around and run and alert the villagers. He should flee onsite and save himself before he’s snatched away.

He should. But he doesn’t.

Instead, he hears himself declare. “I’m going to protect you.”

* * *

He followed the sound and it led him to a giant tree, its trunk big enough for a fully-grown adult to camp in. Iwaizumi knows he shouldn’t be in this side of the forest. His parents had warned him. Many get lost in the acred-woods but the crying sound was like a trance and without thinking too much, he follows it.

Iwaizumi peeks at the hole in the tree and to his surprise realize the sound was coming from inside it. Or rather, from a cloaked form inside it.

“Are you hurt?” Little Iwaizumi asks. Crying means someone was in pain. And Iwaizumi doesn’t like seeing anybody in pain.

The form jolts to life, like it didn’t expect anyone to find him. Underneath the hood, Iwaizumi could see big brown eyes filled with tears looking up at him with relief and joy and _fear._

“Are you hurt?” He asks again, crouching down to level with the boy. He raises his lamp and the figure scurries back. “Don’t be scared. I’m not…are you hurt?” He was still crying and really, all Iwaizumi wants is for him to stop.

The boy seems to consider him, like a lost animal and he says in a quiet voice. “You’re not gonna hurt me?”

Iwaizumi actually laughs. “No. Why would I?”

A pause. “’cause you’re a human?”

“Umm…” Iwaizumi doesn’t know how to answer that. “Yes? I mean, I'm not gonna hurt you.”

The boy’s discomfort melts and he gives him a wide smile. “That’s great. I was so sure you’ll hurt me. Mother says I should stay away from mortals but I got lost during our hunt and now I don’t know how to get back.”

“I’ll help you.” Iwaizumi offers cheerily. It’s not every day he gets a playmate almost the same age as him in the village. “Where do you live?”

The boy crawls out of the tree and stands. He’s taller than Iwaizumi. He points at the far side of the forest. “To the East pass the riverbanks.”

“Eh? But no one lives there. Ma said demons lurk in that area and we should avoid it at all cost. They'd take us away.” He takes the boy’s hand, oblivious to the distress the other was showing and pulls him to the direction of the village. “Let’s ask Pa for help. He’s a servant of the chieftain. I’m sure we can help you find your way home.”

“No!” The boy pulls his hand roughly away. The fright that Iwaizumi had seen before became more prominent in his brown eyes. “You can’t take me there. They’ll kill me. I knew it! You’re a liar. You want to burn me and cut out my heart.”

“What? What are you saying?”

“Don’t touch me. Don’t come near me!”

Iwaizumi does. He knows a tantrum when he sees one and he knows what can help because his Ma does it to him occasionally when he gets upset. He hugs the younger boy who immediately stops his outburst. “There, there, I’m sorry. I won’t take you back home with me if that’s what you want. So, don’t cry anymore, okay?”

It was heating up for some reason. The boy eventually returns the hug and even sniffs Iwaizumi’s neck. “What’s your name?” He asks.

Ma told him never to approach strangers much less give his name.

He's known to break some rules now and then though.

“Iwaizumi Hajime.”

He could feel the boy’s smile against his shoulder. “Hello, Iwa-chan. My name’s Tooru.”

**Author's Note:**

> Next chapter would be Oikawa's POV (T-T) 
> 
> I wrote this in a day because I was getting too emotional and I need an outlet asap. 
> 
> So, if you guys didn't get the plot a bit: we start at a modern setting where the two reincarnate and finally reunite going down to Iwa killing Oikawa, coming back alive and dying from a great war and some fluff moments and how they met (explanations on why Oiks became a pure demon and not remembering Iwa and all other loose ends would be nxt chap :>) Again, this is in reverse order.
> 
> I know the demon Oikawa is a cliche trope but I can't help it. I'm a masochist and a massive Iwaoi sucker. I got my inspiration for the plot of this on an IwaOi amv. I'll find it and link it on the next chapter because that video was awesome!


End file.
